#pragma GCC optimize("O3")
#include<bits/stdc++.h>
using namespace std;
int n;int m;
pair<pair<int,int>,int>ar[500005];
int freq[500005];
int freq2[500005];
int ans[500005];
int fans[500005];
void chk(){
for(int i=1;i<=m;i++){
if(ans[i]){
fans[ar[i].second]=1;
freq[ar[i].first.first]++;
freq[ar[i].first.second+1]--;
}else{
freq2[ar[i].first.first]++;
freq2[ar[i].first.second+1]--;
}
}
for(int i=1;i<=n;i++){
freq[i]+=freq[i-1];
freq2[i]+=freq2[i-1];
if(freq[i]==0||freq2[i]==0){
cout<<"impossible\n";exit(0);
}
}
}
signed main(){
cin>>n>>m;
for(int i=1;i<=m;i++){
cin>>ar[i].first.first;
cin>>ar[i].first.second;
ar[i].second=i;
}
sort(ar+1,ar+m+1);
int stx=0;int sty=0;int xrr=1;
priority_queue<pair<int,int>>pq;
for(int i=1;i<=m;i++){
if(ar[i].first.first<=stx+1&&ar[i].first.second<=sty){
stx=max(stx,ar[i].first.second);
continue;
}
if(ar[i].first.second<=sty){continue;}
if(ar[i].first.first>stx+1){
ans[i]=1;
sty=ar[i].first.second;
continue;
}
pq.push({ar[i].first.second,i});
if(pq.size()==2){
int r1=pq.top().first;int id1=pq.top().second;
int r2=pq.top().first;int id2=pq.top().second;
if(r1>sty){
sty=r1;
stx=r2;
ans[id1]=1;
}else{
stx=max(stx,r1);
sty=max(sty,r2);
ans[id2]=1;
}
pq.pop();
pq.pop();
}
}
chk();
for(int i=1;i<=m;i++){
cout<<fans[i];
}
}
Compilation message
alternating.cpp: In function 'int main()':
alternating.cpp:46:25: warning: unused variable 'xrr' [-Wunused-variable]
46 | int stx=0;int sty=0;int xrr=1;
| ^~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
8540 KB |
Output is correct |
2 |
Correct |
1 ms |
8540 KB |
Output is correct |
3 |
Incorrect |
1 ms |
8540 KB |
'impossible' claimed, but there is a solution |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
8540 KB |
Output is correct |
2 |
Correct |
1 ms |
8540 KB |
Output is correct |
3 |
Incorrect |
1 ms |
8540 KB |
'impossible' claimed, but there is a solution |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
8540 KB |
Output is correct |
2 |
Correct |
1 ms |
8540 KB |
Output is correct |
3 |
Incorrect |
1 ms |
8540 KB |
'impossible' claimed, but there is a solution |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
39 ms |
10664 KB |
Output is correct |
2 |
Correct |
1 ms |
8540 KB |
Output is correct |
3 |
Correct |
21 ms |
10680 KB |
Output is correct |
4 |
Correct |
22 ms |
10588 KB |
Output is correct |
5 |
Incorrect |
45 ms |
10836 KB |
'impossible' claimed, but there is a solution |
6 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
8540 KB |
Output is correct |
2 |
Correct |
1 ms |
8540 KB |
Output is correct |
3 |
Incorrect |
1 ms |
8540 KB |
'impossible' claimed, but there is a solution |
4 |
Halted |
0 ms |
0 KB |
- |